Themes would be nice

I have seen a couple posts on multiple platforms about adding themes and I think themes would be super cool! With the new update (which I think is a great idea, really nice, clean, and fresh), a lot of people are against the change, so making it so people can change the theme to "Classic" or "OG" or whatever you want to call it would be nice resolve a lot of this conflict. And they could go beyond just the new and old looks too; allowing people the change colors and fonts would be insanely awesome. But letting people choose between the new and old look would be a good start.